JPS6231203A - Glass antenna - Google Patents

Abstract

PURPOSE:To remove projections on a surface of a window pane and to improve visuality by forming an antenna pattern on the pane surface constituting the pattern of an antenna element and lead wires specified at their items and connecting these lead wires to parallel feeders. CONSTITUTION:The antenna pattern 30 for a half-wavelength non-grounded antenna for transmitting/receiving a UHF band is formed together with the lead wires on the window pane 10 and connected to the parallel feeders 44 on the end part of the pane 10. The pattern 30 consists of the half-wavelength antenna element 32 arranged in the vertical direction and a leading part 34 extended up to the edge of the pane 10. The pattern 30 is extremely thinly fixed on the surface of the pane 10 by vapor deposition or the like. The lead wires 40, 42 are connected to the parallel feeders 44. In the leading part 34, the center interval S between the lead wires 40, 42 and the wire width W1 are formed with the prescribed size so that impedance matching with the feeder side and VSWR are optimized. In addition, a coaxial feeder can be also used and in this case, the center line width of the lead wire, the inner width of an external lead wire and the width of the external lead wire are set up to the prescribed size.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is used for transmitting/receiving antennas in automobiles such as personal radios and car telephones, and is particularly applicable to glass antennas formed on glass surfaces such as window glass. Regarding.

[Conventional technology]

Conventionally, personal wireless (903-905 former Iz),
UH such as car phones (870-940 Mllz)
Most FHF band receiving antennas are vertical rod antennas.

Since this vertical rod antenna protrudes from the outside of the vehicle, it has drawbacks such as poor car washability and garaging, the possibility of theft and breakage accidents, and wind noise and adverse effects on vehicle design.

In order to eliminate these drawbacks, it is conceivable to use a glass antenna to form a UHFHF band receiving antenna.

[Problem that the invention seeks to solve]

However, as shown in FIGS. 3 and 4, it is possible to directly connect the parallel feed line 18 from the outside to the radiating element 14, 16 of the non-grounded antenna 12 of, for example, λ/2 formed on the automobile window glass IO. As shown in FIGS. 5 and 6, if you try to connect the coaxial feeder line 2g directly from the outside to the radiating element 22° grounding element 24, 26 of the ground antenna 20 of λ/4 formed on the automobile window glass IO, window glass, 10
Produces a protrusion approximately 5 to 101 meters above. As a result, visibility through the automobile window glass 10 becomes poor, the aesthetic appearance is impaired, and the parallel power supply line 18. There is a drawback that the coaxial feeder line is easily disconnected and the reliability of the device is low.

The present invention was made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a glass antenna that can eliminate protrusions on the glass surface, improve visibility, improve appearance, and improve the reliability of the device. , the purpose.

c Means for Solving the Problem] In the glass antenna according to the first invention, an antenna pattern is provided on the glass surface, the antenna pattern is formed from an antenna element and a leader line, and the leader line is connected to a parallel feed line. When connecting, the center spacing S of the leader wires, the line width W1, the dielectric constant ε8 of the glass, and the characteristic impedance z0 of the feeder wire.
As, Z. =27615]τ・It og (2S
/W', ) are set.

Further, in the glass antenna according to the second invention, an antenna pattern is provided on the glass surface, and this antenna pattern is formed from an antenna element and a leader line, and when the leader line is coaxially connected to the feed line, Assuming the center line width d of the line, the inner width D of the external leader line, the outer line width W2, the dielectric constant ε5 of the glass, and the characteristic impedance Z0 of the feed line, z; =138 /FT-ffog(D/d)W, =
d, D, and W are set to satisfy 5 to 10.

[One example]

An embodiment of the present invention will be described based on FIG.

FIG. 1 shows an antenna pattern 30 of a wavelength ungrounded antenna for UHFHF band reception, including a leader line, provided on the front, rear, side, etc., of an automobile window glass 10, and parallel feeding at the end of the automobile window glass 10. A case where it is connected to the electric wire 18 is shown.

The antenna pattern 30 includes an antenna element 32 arranged in the vertical direction and having a predetermined length (half wavelength), and an automobile window glass 10 extending from the center of the antenna element 32 in an orthogonal direction.
It consists of a drawer part 34 extending to the edge of.

The antenna element 32 consists of a pair of linearly arranged radiating elements 36,38. Further, the lead-out portion 34 consists of two lead-out lines 40.42 connected to each radiating element 36.38.

The antenna pattern 3o configured in this way is pasted,
It is fixed on the surface of the automobile window glass 10 by vapor deposition or the like, and its thickness is very thin, for example, about 0.05]τ.

A parallel feed line 44 is provided at the end of the pair of lead wires 40 and 42.
is connected to.

The lead-out portion 34 has a center distance S between the pair of lead-out lines 40 and 42,
The line width W is formed to have a predetermined dimension, and impedance matching with the power supply line side and VSWR optimization are achieved.

Next, S and W will be specifically explained.

First, the characteristic impedance Z0 of the parallel feed line 18 itself shown in FIGS. 3(a) and 3(b) is as follows: εS: Relative dielectric constant of the outer jacket So: Center spacing between two parallel conductors W': Between the conductors It is the diameter.

, substitute the dielectric constant of glass 61″46.5 into (1),
When calculating S'/W' when zo=so(Ω), S
'/W' = 1.45. According to experiments, even if S/W is set to 1.45 in the lead-out portion 34 of the antenna pattern 30 in FIG. It does not become -50 [Ω], S/W, =1
．． 2.5 (S = 2.5, W, = 2), Z when VSWR≦1.5 (transmittable range). #50
Ω].

This means that the entire periphery of the drawer portion 34 is covered by the automobile window glass 1.
It is thought that the deviation occurred from a place not covered by 0. Therefore, if we add this deviation to the relative permittivity ε, we get
Apparent dielectric constant ε of glass is 1. is the true dielectric constant ε
It was found that this corresponds to 74% of the total.

Therefore, the characteristic impedance Z of the lead-out portion 34.

teeth, becomes.

By setting S + and W + of the lead-out portion 34 using this formula, the lead-out portion 34 becomes electrically equivalent to the parallel power feeding '4344, and can be reoriented.

Next, a second embodiment of the present invention will be described based on FIG.

Figure 2 shows LIHF including a leader line in an automobile window glass IO.
A case is shown in which an antenna pattern 50 of a 1/4 wavelength grounded antenna for both body transmission and reception is provided and connected to the coaxial feed line 48 at the end of the automobile window glass 10.

The antenna pattern 50 includes a radiating element 52 arranged in the vertical direction and having a predetermined length of 1/'4 wavelength), and a radiating element 52 arranged in the left and right horizontal directions from near the lower end of the radiating element 52 and having a predetermined length of 172 wavelengths). an antenna element 58 consisting of a pair of grounding elements 54 and 56 forming a pseudo ground plane; We are prepared.

The drawer section 60 has a radiating element 52. It consists of three lead wires 62,64°66 extending from the ends of the grounding elements 54,56.

The antenna pattern 50 configured in this way can be pasted,
It is fixed on the surface of the automobile window glass 10 by vapor deposition or the like.

The three leader lines 62, 64, and 66 have automobile window glass 1.
It is connected to the coaxial feeder line 46 at the edge of 0.

The leader part 60 is formed to have a line width d of the center side leader line 62, an inner width D between the outer leader lines 64 and 66, and a line width W2 of the outer leader lines 64 and 66 to a predetermined size. , impedance matching with the power supply side and optimization of VSWR are achieved.

Next, d, D, and W will be specifically explained.

First, the characteristic impedance Z0 of the coaxial feed line 28 itself shown in FIGS. 4(a) and 4(b) is as follows: ε8: relative permittivity of the filler D': inner diameter of the outer conductor do: outer diameter of the inner conductor.

The lead-out portion 60 is configured by converting the coaxial feeder line 46 into a planar shape.

Substituting the relative dielectric constant ε of glass, #6.5 into equation (4), Z
Calculating D'/d' when 0°=50 [Ω] is D'
/d'=8.39. According to experiments, in the drawer part 60 of FIG.
/ d = 8.39 does not result in Z = 50 CΩ], and D/ d = 2 (d = 1 layer 1, D = 2 s)
), and when W2 = 10m, VSWR≦1
．． Z within the range of 5. It becomes 50 [Ω].

This means that the entire periphery of the drawer portion 60 is covered with the automobile window glass 1.
0. This is because the coaxial feeder line 46 has a flat shape.

First, by renormalizing the deviation of the characteristic impedance from equation (4) into the relative permittivity ε3, the apparent relative permittivity of the glass ε,
f corresponds to 10.6% of the true dielectric constant ε.

Therefore, the characteristic impedance Z0 of the lead-out portion 60 is as follows.

The glue d of the drawer part 60 is set using this formula.

Furthermore, in the case of this pull-out portion 60, the size of W2 greatly influences the validity of equation (4), as described above. This is because since the lead wires 64 and 66 are provided in a plane, a large area is required to have the same grounding effect as the outer conductor of the coaxial feeder line 46.

Therefore, in addition to equation (4), the glue, d, and W of the drawer portion 60 are set so that the condition of Wz/d=5 to 10 (5) is also satisfied.

By setting , the lead-out portion 60 becomes electrically equivalent to the coaxial feeder line 46 .

〔Effect of the invention〕

As explained above, according to the present invention, the leader line of the conductor pattern is arranged for an arbitrary length from the antenna element to the glass edge to have the same characteristics as the parallel feed line or the coaxial feed line. Since there is no protrusion on the top of the drawer, visibility is improved and the appearance is good, and the drawer will not come off even if touched by accident, improving reliability. has.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a glass antenna according to an embodiment of the first invention, FIG. 2 is a schematic diagram showing a glass antenna according to an embodiment of the second invention, and No. 3V is a schematic diagram showing a glass antenna according to an embodiment of the second invention. A schematic diagram showing an example of a glass antenna, FIG. 4 is an enlarged cross-sectional view taken along the rV-rV line in FIG. 3, FIG. 5 is a schematic diagram showing another example of a glass antenna without a leader line, and FIG. The figure is an enlarged cross-sectional view taken along the line -vr in FIG. 5. 10... Automobile window glass, 18.44... Parallel feed line, 28.46... Coaxial feed line, 30.50... Antenna pattern, 34.60... Drawer part, 40.42 .62, 64.66...Leader line.

Claims (2)

[Claims] (1) When an antenna pattern is provided on the glass surface, this antenna pattern is formed from an antenna element and a leader line, and the leader line is connected to a parallel feed line, the center distance S of the leader line, the line width W_1, As the relative dielectric constant ε_s of glass and the characteristic impedance Z_0 of the feeder line, Z_0=276/√Vαε_s・log(2S/W_1
A glass antenna characterized in that S and W_1 are set so as to satisfy ). (2) When an antenna pattern is provided on the glass surface, this antenna pattern is formed from an antenna element and a leader line, and the leader line is coaxially connected to the feeder line, the center line width d of the leader line, Assuming the inner line width D, the outer line width W_2, the dielectric constant ε_s of the glass, and the characteristic impedance Z_0 of the wire, Z_0=138/√βε_s・log(D/d)W_2
A glass antenna characterized in that d, D, and W_2 are set so as to satisfy =5 to 10.